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9.4 Linear Referencing Towards Referent
9.4.1 Target namespace
All schema components specified in this subclause are in the target namespace: http:www.opengis.netgml3.3lrtr
9.4.2 Introduction
Linear Referencing Towards Referent includes the specification of linearly referenced locations which can have a towards referent in their distance expressions.
9.4.3 DualAlongReferent
complexType name=DualAlongReferentType complexContent
extension base=gmllr:AlongReferentType sequence
element name=towardsReferent type=gmllr:ReferentPropertyType minOccurs=0
sequence extension
complexContent complexType
element name=DualAlongReferent type=gmllrtr:DualAlongReferentType substitutionGroup=gmllr:AlongReferent
gmllrtr:DualAlongReferent implements ISO 19148 LRTR_DualAlongReferent see ISODIS 19148, 6.3.3.
For Linear Referencing Methods having a gmllrtr:type of relative, the gmllrtr:DualAlongReferent specifies an optional towards referent.
The optional element gmllrtr:towardsReferent specifies a second location along the gmllr:LinearElement to help disambiguate the gmllr:fromReferent and the direction in which the
measurement is made. The gmllrtr:towardsReferent overrides the directional sense of the gmllr:LinearElement, and may influence the offset direction if an offset is included. When a
gmllrtr:towardsReferent is part of a distance expression, the gmllr:distanceAlong value is measured along the gmllr:LinearElement, beginning at the location specified by the
gmllr:fromReferent
in the direction towards the gmllrtr:towardsReferent. A
gmllrtr:towardsReferent is only appropriate for Linear Referencing Method with towards referent, for example, the cross-street Linear Referencing Method.
9.4.4 DualAlongReferentPropertyType
complexType name=DualAlongReferentPropertyType sequence minOccurs=0
element ref=gmllrtr:DualAlongReferent sequence
attributeGroup ref=gml:AssociationAttributeGroup complexType
A property that has a dual along referent as its value domain may either be an appropriate dual along referent encapsulated in an element of this type or an XLink reference to a remote dual along referent where remote
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includes dual along referents located elsewhere in the same document. Either the reference or the contained element shall be given, but neither both nor none.
9.5 Linear Referencing Offset